Ring made of expanded polystyrene for a cup

ABSTRACT

The present invention solves a number of practical problems relating to the use of disposable plastic and paper cups ( 1 ) by mass caterers and fast food entities for serving beverages such as coffee, tea, juices, refreshments, beers, etc., to their customers but also desserts such as yoghurt, ice cream, fruit salads etc. The ring ( 2 ) has a truncated cone shape to fit externally onto existing disposable cups, plastic or paper and is made of expanded polystyrene. The additional ring covers over  80 % of the total surface, of the beaker in order to heat-insulate and maintain the desirable beverage temperature for longer.

A) GENERAL—OVERVIEW OF THE COGNITIVE FIELD

The present invention relates to the addition of a ring made of expandedpolystyrene to a disposable (plastic or paper) cup. This ring is appliedto the outer surface of the cup covering over 80% of its total surface,with a view to insulating and maintaining the desirable temperature ofthe beverage for a longer period (FIG. 1).

Disposable cups are used by mass caterers and fast food entities forserving beverages such as coffee, tea, juices, soft drinks, granites,beers, etc, to their customers as well as desserts such as yoghurt, icecream, fruit salads, etc. In many cases, customer service is carried outby distribution. Most of these cups do not have any thermal insulationand so the temperature of the contents changes very quickly. Disposablerings to date are mainly paper-made and are available in differentshapes, either flat or corrugated ones and with different closuremethods, as there are also double-walled paper cups, but the cost ofproducing all of these and their heat-insulating behaviour is notsatisfactory. Depending on their type, beverages are distinguished inhot and cold ones. Hot beverages have a high temperature as most areprepared at temperatures slightly above 90° C. and are served attemperatures of 45-50° C. Cold beverages are served at temperaturesbelow 10° C. Given that the indoor temperature of a typical buildingwherein these beverages and foods are served ranges from 20° C. (winter)to 26° C. (summer) and disposable cups are made of plastic or papermaterial with a small wall thickness ranging from 1 to 1.5 millimetres,beverages and foods exchange their heat content very quickly with theenvironment, resulting in their temperature reaching very quickly at alevel very close to ambient temperature. Thus, the offered beverage orfood loses very quickly a basic quality characteristic thereof, i.e. thedesirable consumption temperature. The additional ring (2) of thepresent invention has a truncated cone shape to be applied externally tothe existing disposable, plastic or paper cups (1) (FIG. 2) put on themarket and is made of expanded polystyrene.

Maintaining the desirable temperature of the individual beverage or foodcan be achieved by adding the heat insulating ring to the cup. This isachieved as the coefficient of thermal conductivity of polystyrene isλ_(EPS)=0.035 W/mK and is lower than both the paper coefficient that isλ_(paper)=0.13 W/mK and the polyethylene one λPET=0.20 W/mK. Therefore,the addition of the polystyrene ring will reduce the rate of heattransfer to the environment as the thermal transmittance coefficient bythe addition of the thermal insulation ring will be reduced by 5 to 8times. Below is an illustrative example of calculating the thermaltransmittance coefficient U for case (a) where we have a plastic cup ofpolyethylene without the addition of the ring and (b) where we have aplastic cup of polyethylene with the addition of the thermal insulationring.

Case (a) Coefficient of Layer thermal Thermal thickness d conductivity λresistance d/λ Element layers (mm) (W/mK) (m² * K/W) Polyethylene 1 0.20.005 Total: 0.29 0.005

From the foregoing, the thermal transmittance coefficient is calculated:

$U_{a} = {\frac{1}{\sum\limits_{j = 1}^{1}\frac{d_{j}}{\lambda_{j}}} = {\frac{1}{0{.005}} = {200\mspace{14mu} {W/( {m^{2}K} )}}}}$

Case (b) Coefficient of Layer thermal Thermal thickness d conductivity λresistance d/λ Element layers (mm) (W/mK) (m² * K/W) Polyethylene 1 0.20.005 Expanded 1 0.035 0.029 polystyrene Total: 0.29 0.034

From the foregoing, the thermal transmittance coefficient is calculated:

$U_{\beta} = {\frac{1}{\sum\limits_{j = 1}^{2}\frac{d_{j}}{\lambda_{j}}} = {\frac{1}{0.034} = {29.41\mspace{14mu} {W/( {m^{2}K} )}}}}$

B) DESCRIPTION OF ADVANTAGES OF THE PRESENT INVENTION

The present invention provides a solution to several practical problemsrelating to the use of disposable plastic cups by mass caterers and fastfood entities for the needs of serving beverages such as coffee, tea,juices, soft drinks, beers to their customers, but also desserts likeyoghurt, ice cream, fruit salads etc.

The advantages of this invention are in detail the following:

-   -   1. Maintain the desirable hot or cold beverage and cold meal        temperature for a long time. Maintaining the desirable        temperature of the hot or cold beverage and cold meal is        achieved by using the heat insulating ring for a long time, thus        the user receiving a qualitatively superior product.    -   2. Easy stacking, as due to the truncated cone shape the rings        can be stacked easily in one another (FIG. 3) and thus easily        stored.    -   3. In the case of cold drinks, condensation of water vapour on        the outside of the cup wall (shell) is avoided. This avoids the        unpleasant effect of wetting of the user's hands and the table        on which the cup is placed and, sometimes, dropping of water        drops on the user.    -   4. In the case of a hot drink, it protects the user from the        high temperature of the beverage as the outside wall temperature        coming into contact with the user is very low and can not cause        any burn sensation or burning.    -   5. It is applied to all existing disposable plastic and paper        cups available on the market. On the large base of the truncated        cone there are small notches (3), FIG. 1 (b), to achieve a        perfect fit in a cup with embossed surfaces.    -   6. It does not prevent the simultaneous use of existing bases        and carrying bags for plastic and paper cups.    -   7. It covers up to 80% of the conical surface of the disposable        cups and thus helps maintain the desirable content temperature        for a long time.    -   8. It does not need to be assembled, it has no clasp and it is        ready for use by placing it under the disposable cup.    -   9. It is possible to print a logo on the outer surface of the        ring.

C) DESCRIPTION OF DRAWINGS

FIGS. 1 (a)-(b) show a three-dimensional beverage cup illustration withthe insulating material in two different types, without and withnotches.

FIGS. 2 (a)-(c) illustrate how to place the insulating ring to thedisposable cup.

FIG. 3 shows how the thermal insulation ring is stacked.

1. An additional ring of expanded polystyrene for a disposable cup,characterized in that it is in the foam of a truncated cone, fits to thecup (1) and covers at least 80% of its surface.
 2. An additional ring ofexpanded polystyrene for a disposable cup according to claim 1,characterized in that on the large base of the ring (2) there arenotches (3) for its fitting to a cup (1) with embossed surfaces.